The present teachings are predicated upon providing one or more improved pin caps for placement on a pin and for use in a disc brake system for use with vehicles. For example, the disc brake system may be used with almost any vehicle (e.g. car, truck, bus, train, airplane, or the like). Alternatively, the disc brake system may be integrated into assemblies used for manufacturing or other equipment that require a brake such as a lathe, winder for paper products or cloth, amusement park rides, wind turbines, or the like. However, the present teachings are most suitable for use with a passenger vehicle (e.g., a car, truck, sports utility vehicle, or the like).
Generally, a braking system includes a rotor, a caliper body, two or more pins, a support bracket, an inboard brake pad, and an outboard brake pad that are on opposing sides of the rotor. The caliper body further includes one or more fingers, one or more piston bores, and a bridge that connects the one or more fingers to the piston bore or two opposing piston bores together. The piston bore houses a piston. The piston bore has a bore axis that the piston moves along during a brake apply and a brake retract. The piston bore may include a fluid inlet, a closed wall, a front opening, and a cylindrical side wall that includes a seal groove located near the front opening. Typically, the fluid inlet is located in the closed wall of the piston bore so that when pressure is applied the fluid will flow into the piston bore. During a pressure apply the fluid will push the piston towards the front opening and into contact with a brake pad that generally includes a pressure plate and friction material and the friction material will contact the rotor on one side and the caliper will slide a pin until the opposing brake pad contacts the rotor on an opposing side creating friction to stop rotation of the rotor and any component connected to the brake system. Alternatively, in a system with opposing pistons the caliper is supported by pins and the opposing pistons move opposing brake pads simultaneously into contact with the opposing sides of the rotor. The pin extends into a pin bore in the caliper, the support bracket, or both and during a braking event the pin moves within the pin bore so that the brake pads, the caliper, or both may not be normal to the rotor, the support bracket, or both. Attempts have been made to bias the pin, however, there remains a need for a device that aligns the pins within a pin bore during running, a braking event, or both.
Examples of braking systems that include a pin and/or a device to bias a pin may be disclosed in U.S. Pat. Nos. 4,060,154; 4,235,313; 4,334,598; 4,401,194; 4,447,066; 4,574,922; 4,762,206; 4,781,273; 4,926,979; 5,036,957; 5,183,136; 5,299,665; 5,927,446; 5,931,267; and 6,725,981; U.S. Patent Application Publication No. 2004/0188191; European Patent No. EP0510742; and Japanese Patent No. JP08002504 all of which are expressly incorporated herein by reference for all purposes. It would be attractive to have a device that biases a pin within a pin bore so that the pin is aligned within the pin bore. It would be attractive to have a device that connects to a pin and retains the pin within a pin bore so that the pin is moveable without lubricant, the device is free of derogation, free of loss of restitution, or a combination thereof. What is needed is a device that maintains a pin within a pin bore so that the pin is substantially free of movement within the pin bore during running such that the pin is free of rattle within the pin bore.